To save a copy of your server you need to download the players, plugins and worlds folders to your PC by FTP.
If you need to restore a backup then you have to:
- Stop the server
- Delete the players, plugins and worlds folders from the server
- Upload your copy of the players folder
- Start the server and then stop and delete the plugins and worlds folders that were created
- Upload your copy of the plugins folder
- Start the server and then stop and delete the worlds folder that was created
- Upload your copy of the worlds folder
- Start and test the server